This invention relates to an improved electromagnetically controlled fluid valve. Pneumatic systems offer the possibility of high power, fast performance and economical control. At the same time, semi-conductor developments have made complex electrical signal processing available at a very low cost. To apply the benefits of electrical signal processing, and, in particular, digital signal processing to pneumatic systems, interface transducers between the electrical signals and pneumatic switches are needed. In addition to providing this interface, it would be desirable to develop a device that would not only be inexpensive to manufacture but also have very low electrical power consumption. This would enable the interface to obtain its electrical power from the same source as the semi-conductor logic.
Heretofore, Bremner et al in U.S. Pat. No. 3,203,447 issued Aug. 31, 1965 for a Magnetically Operated Valve, described a device which interfaced electrical signals and with a pneumatic valve. The Bremner et al patent teaches that a magnetically polarized valve member may be switched or shuttled between valve seats by means of an electromagnetic coil which controls the magnetic field. Switching of the valve is dependent upon the summation of magnetic flux fields of a permanent magnet and an electromagnet.
While such a magnetically operated valve appears to be operable, an improved valve has been sought which much more efficiently charges the permanent magnet force and thereby will quickly switch in response to short term, low power electromagnetic signals. It is this motivation which led to the following described electromagnetic fluid valve.